Merge branch 'duplicated-process' into 'master'

Avoid duplicated processes when filtering with unscheduled

Closes #505

See merge request !1039

arkindex/dataimport/api.py

@@ -167,7 +167,7 @@ class DataImportsList(CorpusACLMixin, ListAPIView):
             if state == State.Unscheduled:
                 # Handle a workflow with no task as unscheduled
                 state_query |= Q(workflow__tasks__isnull=True)
-            qs = qs.filter(state_query).exclude(id__in=excluded_imports.values('id'))
+            qs = qs.filter(state_query).exclude(id__in=excluded_imports.values('id')).distinct()
 
         return qs.order_by('-last_task')